Radio Device Clock Deviation Management for Power Savings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless communication systems face power consumption issues due to inadequate management of frequency offsets and temperature variations in low power clock drifts, leading to reduced battery life in mobile devices.

Innovation Solution

A radio device with a first clock unit for active mode and a second clock unit for sleep mode, which determines and indicates temperature and frequency deviations to the processor, allowing the processor to switch from sleep to active mode accordingly, using a temperature compensated MEMS oscillator and Phase-Locked Loop to compensate for frequency variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If safety margins are increased to account for temperature variation and frequency offsets, then reliability is improved, but power consumption increases

Engineering Contradiction:
ImprovereliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic adjustment of sleep window duration based on real-time temperature measurements and frequency offset calculations. The system transitions from static safety margins to dynamic adaptation, extending sleep windows when conditions permit and shortening them when frequency drift exceeds thresholds, thereby resolving the contradiction between reliability and power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system continuously monitors temperature variations and calculates frequency offsets, using this feedback to adjust sleep window duration and wake-up timing. This closed-loop control enables the system to maintain reliability while minimizing power consumption by avoiding unnecessarily early wake-ups.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If sleep window duration is extended to save power, then power consumption is reduced, but frequency offset accuracy deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoidfrequency offset accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent performs preliminary temperature measurement and frequency offset calculation before the sleep window expires. By predicting the frequency offset at wake-up time based on temperature gradients, the system can prepare calibration data in advance, maintaining measurement accuracy even with extended sleep durations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically calculates frequency offset based on real-time temperature measurements and temperature gradient data. This dynamic approach allows the system to extend sleep windows while maintaining frequency offset accuracy through continuous environmental monitoring and predictive calculations.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If temperature compensation is implemented to reduce frequency drift, then frequency stability is improved, but device complexity increases

Engineering Contradiction:
Improvefrequency stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements self-service temperature compensation where the low-power clock unit autonomously measures temperature, calculates frequency offsets, and provides correction data to the processor. This self-contained approach improves frequency stability without requiring complex external compensation circuits, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system merges temperature sensing and frequency compensation functions into the low-power clock unit itself. By combining these functions in a single integrated unit rather than separate components, the patent achieves frequency stability through temperature compensation while minimizing the increase in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution extends the sleep window duration, reduces power consumption, and ensures timely wake-up to avoid missed paging channel monitoring, thereby enhancing battery operation time and reducing current consumption.

Implementation Method 1

using a temperature compensated MEMS oscillator and Phase-Locked Loop to compensate for frequency variations

Methodology Applied
Scientific EffectTemperature compensation:

Implementation Method 2

using a temperature compensated MEMS oscillator and Phase-Locked Loop to compensate for frequency variations

Methodology Applied
Scientific EffectPhase-Locked Loop:

Data Source

PatentEP3402261B1Methods and devices indicating at least one of a temperature and frequency deviation
Publication Date: 2020.06.17 APPLE INC
  • EP3402261B1 patent drawingFigure 1
  • EP3402261B1 patent drawingFigure 2
  • EP3402261B1 patent drawingFigure 3

AI summary

The disclosure relates to a radio device, comprising: a first clock unit; a second clock unit configured to run at a lower clock rate than a clock rate of the first clock unit; and a processor configured to operate based on the first clock unit in an operation mode and based on the second clock unit in a sleeping mode, wherein the second clock unit is configured to determine at least one of a temperature and frequency deviation of the second clock unit and to indicate the at least one of a temperature and frequency deviation to the processor.